A Tanzanian woman brought to the United States by a diplomat at his country's mission in Washington is suing the envoy and his wife, alleging that they treated her like a slave in their Montgomery County home for more than four years, failed to pay her and physically abused her.

Diplomats in the United States have broad immunity from civil and criminal prosecution, but plaintiff Zipora Mazengo's attorneys say they hope the case will be allowed to proceed because the woman worked for the couple's catering business, which they argue should strip the two of immunity.

The suit, filed late last month in federal court in the District, states that Alan S. Mzengi, a minister at the Tanzanian Embassy, and his wife, Stella, forced Mazengo to work 16-hour days, seven days a week, from June 2000 until she fled in August 2004.

Mazengo, who has a visa from the Department of Homeland Security that is given to victims of human trafficking, said in an interview that she filed the suit to collect unpaid wages and send a message to her former bosses.

"They should be fair," said Mazengo, who is being represented by CASA de Maryland, an immigrant advocacy group.

Alan Mzengi didn't respond to a message left with a woman who answered the phone at his home yesterday. The woman said Stella Mzengi was out of the country. It could not be determined whether they have a lawyer.

Calls to the Tanzanian Embassy went unanswered yesterday.

Mazengo was 20 when she arrived in Washington on a domestic worker visa issued at the request of the embassy.

The lawsuit states that Alan Mzengi drafted a contract stipulating that she would work eight hours a day, five days a week taking care of the couple's house and their children. She would be paid $900 a month, from which $150 would be deducted for room and board. The contract also stated that she would be eligible for overtime pay, according to the lawsuit.

About a month after she started working at the couple's home in Bethesda, Mazengo said, she realized her bosses weren't going to adhere to the terms of the contract. But she felt that she had no recourse, she said, because the couple took her passport and because she spoke virtually no English.

Mazengo said she was forced to work from 6 a.m. to 10:30 p.m. every day caring for the couple's children, cleaning and cooking, according to the suit. Additionally, she cooked for the couple's African food catering business, which they ran from their home, the suit states.

On one occasion, Mazengo said in the interview and in the lawsuit, Stella Mzengi struck her in the face. The couple also refused to take her to a doctor for more than two years as ingrown toenails became so painful she couldn't wear shoes, Mazengo said. Despite her condition, Alan Mzengi "ordered her to shovel snow in her bare feet," according to the suit.

In August 2004, Mazengo said, when she asked Alan Mzengi for her wages, he bought her a one-way ticket to Tanzania and told her she would be paid when she returned home. Mazengo called one of the clients of the catering business, who had been friendly to her, to say goodbye. During the phone call, Mazengo said, she began to weep and told the customer about the conditions she had endured. The customer asked her to take a cab to her home, where she eventually got in touch with CASA de Maryland, Mazengo said.

In December, she received the visa given to victims of human trafficking, a turning point that she says emboldened her to take legal action.

Allegations of human trafficking by diplomats are not unusual, said Mazengo's attorney, Elizabeth Keyes. But she said courts have tossed out every such case she knows, citing diplomatic immunity. However, diplomats can be held liable for violating the law in the course of professional and commercial activities outside the scope of their diplomatic duties, Keyes said. In recent similar cases, she said, plaintiffs have argued that the sole act of hiring a domestic worker falls under the exception for commercial activities, but judges have disagreed.

"This is a novel argument," Keyes said, referring to the catering business. "It's hard to imagine something more commercial than running a small catering business."

Mazengo's lawsuit alleges involuntary servitude, trafficking, forced labor, and state and federal minimum wage violations, among other crimes. She is seeking about $500,000 in back wages and other unspecified damages.

Dar es Salaam has moved fast to pledge its support to Washington, which is investigating claims of human rights abuses against a high ranking Tanzanian diplomat based in the United States. The diplomat Alan Mzengi, is accused of mistreating a fellow national who worked for him as a nanny.

Tanzania's pledge is widely seen as an attempt to play down the highly embarrassing case.

It comes in the wake of last week's outrage by members of the US Congress on hearing the testimony of Zipora Mazengo's account of her four-year-long enslavement by Mzengi, a minister in the Tanzania embassy in Washington.

In fact, the US government is treating the matter so seriously that the chairman of the US House's Foreign Affairs Committee Tom Lantos, who also heard Ms Mazengo's testimony, discussed the case with Secretary of State Condoleezza Rice in a private meeting last Tuesday. The content of their conversation was not disclosed. But Congressman Lantos said earlier that the State Department would be remiss if it does not take punitive action against "a so-called diplomat who exploits in such an outrageous fashion another human being."

Efforts to reach Mr Mzengi were not successful. The Tanzania embassy in Washington did not respond to The EastAfrican's request for comment. But speaking exclusively to The EastAfrican in Dar es Salaam last Thursday, the Permanent Secretary in the Ministry of Foreign Affairs and International Co-operation, Patrick Mombo, said the government was aware of the congressional hearings and that the allegations will be dealt with by the justice system in the US.

He said he had instructed the staff at the embassy to fully co-operate with the US Justice Department and the Department of State in resolving the matter. But he fell short of saying if the diplomat will be recalled over the case, which has left Dar es Salaam red in the face.

In a moving testimony to the Committee, Ms Mazengo recounted how she was abused and forced to work more than 100 hours a week without pay in the home of the diplomat, his wife, Stella and the couple's three children.

She said: "When I made any mistakes, Mrs Mzengi would scream at me. Once when I did not prepare her breakfast, she hit me on the face and sent me out in my summer clothes to stand outside in the snow. She told me that if I complained, &#8216;blood would fall on the floor.'"

And ther accusations continued, "they stole my passport from me. They stole my freedom from me. They stole four years of my life."

Congressman Dan Burton after listening to Ms Mazengo's account, declared that Mr Mzengi, who is apparently still working at the embassy in Washington, should be deported from the United States. "Anybody who treats another human being this way should lose their right to represent their nation in this country, and they ought to be deported immediately," he said.

Ms Mazengo, 27, arrived in the United States from Tanzania in 2000 on a type of visa that diplomats can arrange for prospective nannies and domestic workers. Last December - two years after fleeing the Mzengis' home - she received a special US visa given to victims of human trafficking.

Having gained that protection, Ms Mazengo was emboldened to file a lawsuit against the Mzengis seeking $500,000 in back wages and damages. A court in Washington recently ruled in Ms Mazengo's favour after the Mzengis repeatedly failed to respond to her accusations, which were filed six months ago. The court has scheduled a hearing in December to determine the amount of damages to be assessed.

But it remains to be seen whether Mr Mzengi will actually be required to make such payments.

Diplomats serving in the United States generally enjoy immunity from civil and criminal prosecution, but they can be held liable for crimes committed in the course of non-diplomatic activities. Ms Mazengo's attorneys are arguing that Mr Mzengi's diplomatic immunity does not apply in this instance because Ms Mazengo worked part-time for an African food catering business that the couple operated from their home.

A contract signed by Ms Mazengo and Mr Mzengi stipulated she would be paid $900 a month and would receive two weeks' paid leave per year as well as two days off each week.

"But the Mzengis never paid me," she told the US lawmakers. When she asked for her wages, Ms Mazengo added, the Mzengis "said they would hurt me and send me home." She worked every day for four years, often from 6am until 10.30pm, and was not permitted to leave the house, Ms Mazengo said.

In August 2004, Ms Mazengo said in her lawsuit, one of the clients of the Mzengis' catering business helped her flee the home. The lawsuit charges the Mzengis with violating US laws against forced labour and human trafficking.